Process and composition for sterilizing surgical sutures



United States Patent Q 3,414,370 PROCESS AND COMPOSITION FOR STERILIZ- ING SURGICAL SUTURES Ludwig Baumgartner, Nurnberg, Germany, assignor to Pfrimmer & Co., Erlagen, Bavaria, Germany No Drawing. Filed Jan. 29, 1964, Ser. No. 341,115 Claims priority, application Germany, Jan. 31, 1963, 31

16 Claims. b1. 21-58) ABSTRACT OF THE DISCLOSURE The present invention relates to a process for sterilizing surgical sutures, especially catgut or other synthetic surgical sutures with or without needles by means of ethylene oxide or propylene oxide in alcoholic solution.

It is known in the prior art to add to the alcoholic solution aliphatic hydroxy acids, such as lactic acid, and ammonium hydroxide.

According to the present invention, aliphatic saturated or unsaturated monoor di-carboxylic acids, or aromatic monoor di-carboxylic acids, aromatic phenol carboxylic acids, and organic bases such as alkylolamines or alkylamines are added to or admixed with the alcoholic solution.

In carrying out the process of the present invention, it is understood that mixtures of the aforementioned acids and/ or bases can also be used in any desired proportion.

Accordingly, it is an object of the present invention to provide a process for sterilizing surgical sutures which is simple yet extremely efiective for the intended purposes.

Still a further object of the present invention resides in the provision of a method for sterilizing surgical sutures or the like which utilizes relatively inexpensive ingredients to affect a high degree of sterilization.

A further object of the present invention resides in the provision of a sterilization method and solution suitable therefor which does not require high temperatures for realizing a high degree of sterilization.

These and other objects, features and advantages of the present invention will become more obvious from the following description of several examples of the present invention which is equally applicable to sterilization processes in which the surgical sutures treated with the acidbase mixture according to the present invention are gassed subsequently with ethylene oxide or other epoxides.

The following are illustrative examples of carrying out the present invention, it being understood that they are merely illustrative but not limitative thereof.

Example I 130 ml. of a solution consisting of:

Percent by weight Isopropyl alcohol 90 Ethylene oxide 1.3 Succinic acid 0.8

water is added up to a total composition of 100% adjusted with triethanolamine to a pH factor of 7.2, is

poured into a bottle which contains the suture material to be sterilized. The mixture is left standing for about 14 days at a temperature of about 25 C.

Example II 130 ml. of a solution consisting of:

Percent by weight Isopropyl alcohol Ethylene oxide 1.2

water is added up to a total composition of 0.5 by weight of either benzene carboxylic acid or salicylic acid, brought to a pH factor of 6.5 by means of a base, is poured into a bottle which contains the suture material to be sterilized, and is left for 14 days at a temperature of 25 C.

Example III ml. of a solution consisting of:

Percent by weight Isopropyl alcohol 90 Ethylene oxide 1.2 Sorbic acid 0.5

water is added up to a total composition of 100% adjusted with triethanolamine to a pH factor of 6.8, is poured into a bottle which contains the suture material to be sterilized, and is left standing for 7 days at a temperature of about 30 C.

Example IV Suture material of diameter 1 (according to USP XVI) is treated for about one day with a solution consisting of:

Percent by weight Isopropyl alcohol 90 Succinic acid 0.5

water is added up to a total composition of 100% and brought to a pH factor of 6.8 by means of triethanolamine. Subsequently, the thus treated sutures are welded into a polyethylene foil and sterilized by gassing with ethylene oxide.

While I have described several examples in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible to numerous changes and modifications as known to a person skilled in the art. For example, the acids may consist of any saturated (such as acetic acid) or unsaturated monocarboxylic acids or di-carboxylic acids, aromatic monocarboxylic acids, di-carboxylic acids or aromatic phenol carboxylic acids or mixtures thereof. Any suitable organic base may be used for the present invention such as, for instance, alkylolamines or alkylamines.

Furthermore, in all the examples mentioned hereinabove, subsequent sterilizing treatment by means of suitable sterilizing gases is also within the scope of the present invention.

Thus, while I have described several examples in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible to numerous changes and modifications, and I therefore do not wish to be limited to the illustrative examples described herein, but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

I claim:

1. A method for sterilizing surgical sutures such as catgut or synthetic surgical sutures with or without needles which comprises immersing the sutures into an alcoholic solution containing a small quantity of an epoxide sterilizing agent, a small amount of an acid selected from the group consisting of aliphatic saturated and unsaturated monocarboxylic acids and di-carboxylic acids and aromatic mono-carboxylic acids and dicarboxylic acids and a base present in an amount sufficient to approximately neutralize the acid, said base being selected from the group consisting of alkylamines and alkylolamines, and leaving the sutures in the solution at about room temperature for a predetermined time.

2. The method of claim 1, wherein the epoxide is in the gaseous phase.

3. A solution for sterilizing surgical sutures such as catgut or synthetic surgical sutures with or without needles which comprises an aqueous alcohol solution, a small quantity of an epoxide sterilizing agent, a small amount of an acid selected from the group consisting of acetic acid, succinic acid, sorbic acid, benzoic acid, and salicylic acid and a base present in an amount sufiicient to approximately neutralize the acid, said base being selected from the group consisting of alkylamines and alkylolamines.

4. The solution of claim 3, wherein the base is selected from the group consisting of diethylamine and triethanolamine.

5. A solution for sterilizing surgical sutures such as catgut or synthetic surgical sutures with or without needles which comprises an aqueous alcohol solution, a small quantity of an epoxide sterilizing agent, a small amount of an acid selected from the group consisting of aliphatic saturated and unsaturated monocarboxylic acids and dicarboxylic acids and aromatic mono-carboxylic acids and dicarboxylic acids and a base present in an amount sufficient to approximately neutralize the acid, said base being selected from the group consisting of alkylamines and al-kylolamines.

6. The solution of claim 5, wherein the epoxide sterilizing agent is selected from the group consisting of ethylene oxide and propylene oxide.

7. The solution of claim 5, wherein the base is present in an amount sui'ficient to provide a pH of about 6.5 to 7.2 for the solution.

8. The solution of claim 5, wherein the acid is present in an amount less than 1% by weight.

9. The solution of claim 5, wherein the epoxide is in the gaseous phase.

10. A solution according to claim 5, wherein said acid is acetic acid.

11. A solution according to claim 5, wherein said acid is succinic acid.

12. A solution according to claim 5, wherein said acid is sorbic acid.

13. A solution according to claim 5, wherein said acid is benzene carboxylic acid.

14. A solution according to claim 5, wherein said acid is salicylic acid.

15. A solution according to claim 5, wherein said base is triethanolamine.

16. A solution according to claim 5, wherein said base is diethylamine.

References Cited UNITED STATES PATENTS 2,817,437 12/1957 George et al 2l-58 XR 2,983,750 5/1961 Cotty et a1. 99-224 XR 3,097,996 7/1963 Thoma et a1. 2158 XR 3,234,268 2/1966 Mercia 99224 XR OTHER REFERENCES McCulloch, Ernest C., Disinfection and Sterilization, Lea and Febiger, Philadelphia, 1945 (pp. 234-240 and 249 relied on).

MORRIS O. WOLK, Primary Examiner.

B. S. RICHMAN, Assistant Examiner. 

